Land Suitability Analysis for Sustainable Agricultural Development in Rajshahi District of Bangladesh

Abstract

Importance of land suitability analysis for sustainable agricultural development is unnoticed in Bangladesh for long time resulting in the stagnation of profit margin, economic benefit, yield, crop diversification and development in agriculture sector as well as socio-economic, political and cultural development of Bangladesh. However, the purposes of the present research were land suitability analysis for sustainable agricultural development in Rajshahi district of Bangladesh analyzing the current soil, irrigation water, climate, topography, floodability, and accessibility attributes and many other aspects of the study area. Besides, economic viability of currently cultivated major crops and cropping patterns and land suitability based cropping patterns are assessed. Land use changing patterns are analyzed and farmers’ perception levels are also measured for agriculture development. In this study, Rajshahi district of Bangladesh was the study area and Godagari upazila was selected through simple random sampling (SRS) which covers about 20 per cent area of the district. Soil, irrigation water, topography, and floodability samples and respondents for questionnaire survey and land suitability model output and classified image verification samples were selected using sample size determination formula and union wise samples were selected following probability proportional to size (PPS) sampling. Climate data were used for 40 years (1975-2014) of the study area and accessibility data were generated using multiple ring buffer and Euclidian distance method in GIS technique. Data of economic viability of agricultural crops and farmers’ perception regarding land suitability and agriculture development were collected through questionnaire survey. Land use changes were analyzed considering soil properties of 1991 and 2015, crop cultivation areas of 1983-84, 1996, and 2008 by agriculture census data, agriculture land use changes using 5 images of 1977, 1988, 1996, 2008, and 2016 and cultural changes in different aspects of agriculture of the study area. Total six case studies- two from each of onion seed, cauliflower, and Thai guava cultivation were conducted to support the data. All properties of soil except pH and boron are below from the optimum value in the study area. Irrigation water attributes are within normal range though not in optimum level. Temperature is not a major problem but rainfall is insufficient for crops production. High land area dominates in the study region and flooding problem is very trifling. Accessibility is a major problem for Char Ashariadaha union which is separated by mighty river the Padma. Soil and climate are moderately suitable; irrigation water and floodability are predominantly suitable for agriculture in the study area. Topography and accessibility are found mainly low and moderate suitable for agriculture. The study locale is dominated by agriculture and agriculture is dominated by a few crops mainly rice. All unions are found moderately suitable for rice, wheat, maize, potato, chili crops cultivation and the whole study area is found moderately suitable for general agriculture. On the other hand, lentil, mustard, and onion crop cultivation are found moderately suitable in Basudevpur, Deopara, Gogram, Matikata, Rishikul, Godagari, Mohanpur, and Pakri union which cover 92.34 per cent land area and marginally suitable is found only in Char Ashariadaha union which covers only 7.66 per cent land. In land suitability model output, the accuracy figure was found from 87.50 to 92.85 per cent in field verification. Yield of almost all crops is lower in the study area than that of Northern Bangladesh. Among the generally cultivated 15 crops, per 33 decimals net returns from onion seeds and cauliflower cultivation are found worth about BDT 97574 and 26090 respectively which are very profitable and much more than rice which (rice) is cultivated in about 79 per cent land both in the study area and in Bangladesh. The next economically viable five crops are onion, brinjal, tomato, maize, and potato respectively on the basis of net return. On the other hand, rice is the economically least viable crop and next least viable five crops are mustard, wheat, lentil, chili, and pulses respectively. However, the dominance of rice in cropping patterns in the study area and Bangladesh is not economically viable and a key obstacle for the development of agriculture, socio-economic development of farmers as well as rural areas of Bangladesh. Land suitability based cropping patterns are highly profitable than presently cultivated rice based cropping patterns. It is possible to increase net returns about BDT 511.74, 2398.54, 9512.49, and 97930.14 crores for the study area, Rajshahi district, Rajshahi division, and Bangladesh respectively changing only cropping patterns and agriculture sector alone could contribute a lot to develop Bangladesh if land suitability based cropping patters are followed. Case studies of onion seed, cauliflower, and Thai guava cultivation show that these three crops cultivation are profitable but cauliflower has low sustainability risks and onion seed and Thai guava cultivation have high sustainability risks. pH, organic matter, and zinc level have been increased but nitrogen, phosphorus, sulfur, and boron of soil have decreased significantly in the study area from 1991 to 2015. HYV aus, HYV boro rice, maize, jute, potato, spices, fruits, oil seeds, and vegetables cultivation area have been increased but HYV aman, wheat, sugarcane, pulses cultivation area are decreasing. Agriculture land cultivation areas have been increased noticeably from 1977 to 2016. The classification error matrix of 2016 Landsat 8 image in 56 spots, field verification shows that the classification accuracy is 87.50 per cent. Chi-square value was found 285.430, Kendall’s tau .758 and Kappa statistic was .809 that show good agreement between classified image and field data. Cultural changes are occurred noticeably in agriculture in the study area. Farmers hold medium and low level of perception regarding land suitability and agriculture development in the study area which are not conducive for sustainable agricultural development and need to be elevated for the development of agriculture. The study area has immense potentialities of Thai guava, bablah, moringa, flowers, mango etc. cultivation in agriculture land and fish cultivation in 1162 ha low land area. Land suitability based crop cultivation, crop diversification and cropping pattern changes, emphasis on cultivation of profitable non-traditional crops, application of GIS and RS, e-agriculture, use of organic and green manure fertilizer, fish cultivation and other practices in 1162 ha low lands, establishing agriculture market and cold storages, elevation of farmers’ perception level etc. are few important ways for sustainable agricultural development in the study area.